refactor: extract reusable library

- move reusable domain, data, state, ui code into src/lib
- update host screens to consume new library exports
- document architecture and configure path aliases
- bump astro integration dependencies for compatibility

Refs #30

src/lib/state/useGameState.ts

@@ -0,0 +1,121 @@
+import { useState, useEffect, useCallback } from 'preact/hooks';
+import type { Game, NewGameData, GameFilter } from '@lib/domain/types';
+import { GameService } from '@lib/data/gameService';
+
+export function useGameState() {
+  const [games, setGames] = useState<Game[]>([]);
+  const [filter, setFilter] = useState<GameFilter>('all');
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  // Load games from IndexedDB on mount
+  useEffect(() => {
+    const loadGames = async () => {
+      try {
+        setLoading(true);
+        setError(null);
+        const savedGames = await GameService.loadGames();
+        setGames(savedGames);
+      } catch (err) {
+        console.error('Failed to load games:', err);
+        setError('Failed to load games from storage');
+      } finally {
+        setLoading(false);
+      }
+    };
+
+    loadGames();
+  }, []);
+
+  const addGame = useCallback(async (gameData: NewGameData): Promise<number> => {
+    try {
+      const newGame = GameService.createGame(gameData);
+      await GameService.saveGame(newGame);
+      setGames(prevGames => [newGame, ...prevGames]);
+      return newGame.id;
+    } catch (err) {
+      console.error('Failed to add game:', err);
+      setError('Failed to save new game');
+      throw err;
+    }
+  }, []);
+
+  const updateGame = useCallback(async (gameId: number, updatedGame: Game) => {
+    try {
+      await GameService.saveGame(updatedGame);
+      setGames(prevGames => 
+        prevGames.map(game => game.id === gameId ? updatedGame : game)
+      );
+    } catch (err) {
+      console.error('Failed to update game:', err);
+      setError('Failed to save game changes');
+      throw err;
+    }
+  }, []);
+
+  const deleteGame = useCallback(async (gameId: number) => {
+    try {
+      await GameService.deleteGame(gameId);
+      setGames(prevGames => prevGames.filter(game => game.id !== gameId));
+    } catch (err) {
+      console.error('Failed to delete game:', err);
+      setError('Failed to delete game');
+      throw err;
+    }
+  }, []);
+
+  const getGameById = useCallback((gameId: number): Game | undefined => {
+    return games.find(game => game.id === gameId);
+  }, [games]);
+
+  const getFilteredGames = useCallback(async (): Promise<Game[]> => {
+    try {
+      return await GameService.getGamesByFilter(filter);
+    } catch (err) {
+      console.error('Failed to get filtered games:', err);
+      setError('Failed to load filtered games');
+      return games.filter(game => {
+        if (filter === 'active') return game.status === 'active';
+        if (filter === 'completed') return game.status === 'completed';
+        return true;
+      });
+    }
+  }, [filter, games]);
+
+  const getPlayerNameHistory = useCallback((): string[] => {
+    // Extract player names from current games for immediate UI use
+    const nameLastUsed: Record<string, number> = {};
+    
+    games.forEach(game => {
+      const timestamp = new Date(game.updatedAt).getTime();
+      
+      if ('players' in game) {
+        // EndlosGame
+        game.players.forEach(player => {
+          nameLastUsed[player.name] = Math.max(nameLastUsed[player.name] || 0, timestamp);
+        });
+      } else {
+        // StandardGame
+        if (game.player1) nameLastUsed[game.player1] = Math.max(nameLastUsed[game.player1] || 0, timestamp);
+        if (game.player2) nameLastUsed[game.player2] = Math.max(nameLastUsed[game.player2] || 0, timestamp);
+        if (game.player3) nameLastUsed[game.player3] = Math.max(nameLastUsed[game.player3] || 0, timestamp);
+      }
+    });
+
+    return [...new Set(Object.keys(nameLastUsed))].sort((a, b) => nameLastUsed[b] - nameLastUsed[a]);
+  }, [games]);
+
+  return {
+    games,
+    filter,
+    setFilter,
+    loading,
+    error,
+    addGame,
+    updateGame,
+    deleteGame,
+    getGameById,
+    getFilteredGames,
+    getPlayerNameHistory,
+  };
+}